Encapsulation films offer insulation and environmental protection for electrical components used in electronic devices, such as solar cells used in PV modules. Encapsulants can act as a skin for electronic devices or completely enclose the device.
In the construction of a typical silicon-based photovoltaic (PV) module, there is a front glass layer followed by a front encapsulant, the solar cells, a back encapsulant and, finally, a back sheet. These layers are laminated at elevated temperatures to create the solar module.
The polymer material currently used in the back sheet of a solar module tends to shrink when exposed to the high temperatures necessary to properly laminate the solar module layers. Shrinkage of the back sheet is transferred forward to the other layers of the solar module, causing the individual PV cells within the solar module to be pulled closer together and the ribbons connecting the individual cells to crimp, or bend back against the back sheet.
The back sheet is therefore displaced during lamination. After lamination, visible bumps are present in the back of the solar module, decreasing the module's overall aesthetic appeal. The solar module may also not work properly due to the PV cells' movement and ribbon-crimping experienced during lamination.
Of interest are encapsulant films which prevent the transfer of movement as a result of shrinking from the back sheet of a solar module to the rest of the unit.